Defuddle: XSS via unescaped attribute interpolation in site extractors

Defuddle cleans up HTML pages. Prior to 0.19.1, site extractors interpolate page-derived image alt and src values, og:image values, and video descriptions into HTML strings without context-appropriate escaping, and buildExtractorResponse() returns this contentHtml without the main pipeline's DOM-based sanitization. The affected paths include src/extractors/x-article.ts, src/extractors/substack.ts, and src/extractors/youtube.ts. A malicious page or attacker-controlled content on a matching domain can inject event-handler attributes or javascript URLs that execute when a victim or downstream application renders the extracted HTML. This issue is fixed in version 0.19.1.